Electrical-clutch machine.



W. T. PRICE.

ELECTRICAL CLUTCH MACHINE.

APPLIOATIOH FILED NOV. 20, 1907.

Q19 4 6Q Patented Apr.27,1909

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whitish r. PRIGE, ,OF BUFFALO, NEW YORK.

ELEGTRICAL-C'LUTCH MACHINE.

Etc. emcee.

Specification of Letters Patent.

Patented April 27, 1969.

Appliczition filed November an, 1907. semi No. 403,039.

all whom it may concern:

Be it known that LlVILLIAM 'lunon Pinon, a subject of the King oi: GreatBritain, and a resident of Buiialo, in the Erie and State of New York,have invented a new and useful Electrical-Clutch Machine,

of which the following is a specification.

My, invention relates to improvements in electrical clutch machinesinvolving electrical clutches of the induction type. With this type ofclutch the operation does not depend upon friction but upon the forceexerted on a closed electrical circuit when I moved relative to amagneticfield so that the lines of. force are thereby cut.

My invention is intended, primarily, to start a driven element from auniformly rotating driving element through the agency of my electricalinduction clutch. When the clutches are used in pairs with equivalentmechanical connections to those herein specified, the electrical clutchmachine may then be used not only for starting, but for stopping andreversing the said driven element. great service f r operating rollingmills, roll- 111g mill tables, plane tables, swing bridges,

automobiles and is adaptable for many other individual clutchesniay beused for members which are intended to rotate in but one direction; aline shaft may be started with the electrical induction clutch andbrought to almost the speed of the driving element, then apositivemechanical clutch may bethrown in to supersede the former. Theelectrioalinduction clutch may be loceted in a drive-as a protect've ive theclutch would not transmit it but would slip without injury to itself orits connections.

My electrical induction clutch may be used as in instruments forproducing a torque almost in exact proportion to the speed of itsdriving element. Thus it may be used in tachoineters. My electricalinductiouclutchmay also be .used as a brake The objects of my inventionare? First, to provide a powerful electrical induction clutch or highstarting torque and low running slip. Second, to provide a compactclutch of the above qualities,

in a narrow space and may withstand the rough usage to" whlch suemachines ,are sub1ected. Third, to'provide an electrical county of Thelatter combination would be telement, for should the force become excessv of extremely rig d construction so that it may be located induct-ionclutch wherein pole faces, long in the direction of rotation, may beused withoutexcessively increasing the length of the electrical path inthe rotor. Fourth, to provide a machine by which, from a constantlyrotating driving element, a driven element may he started and stoppedand reversed with high acceleration, without wear or other injury to thevarious drive components. Fifth, to provide an electrical clutch machineof the last named qualities, of compact and attractive design.

The invention is illustrated b the accompanying drawing in which; igure1 is a plan view of the electrical clutch machine; Fig. 2 a sidesectional view of the electrical clutch machine, the near clutch beingremoved; Fig. 3 is a cross section of the electrical induction clutch,showing the driving and the driven members and the bevel gear by whichthe driving clutch member is driven; Fig. 4 is the corresponding endview of the clutch showing also one 01. the bean ings of the electricalclutch machine; Fig. 5 is a diagram, drawn to a larger scale, showingthe. general locations and directionsof the magnetic and electriccircuits when the clutch is operating.

Similar characters refer to similar parts throughout the several views.

B is the bed plate on whichthe machine is assembled, C is the drivingshaft which rotates continuously in one direction; in this particularcase the shaft C is the armature driven by any motivc power. E is thedriving gear.

F, the driven shaft, is journaled in the bearings G, G, andhas mountedthereonxtwo electrical olhtches which are alike In the constructt'onshown, the clutch driving memrotate intheopposite direction,

As statedahoye the'twoclutches are alike and theircbnstruction is asfollows: K is-the magnetic fieldwastihg, preferaol steel shalt of themotor D, but the shaftmay be clutch isfthrown into service the shaftwill casting, on theproiclitmgpoleipinctfiiiith s v hers are looselymounted on the shaft and casting are mounted the electrical windings L,L, etc. hese coils are so connected that when current poles are. ring Mis made of two metals preferably in good electrical contact with eachother though this condition is not imperative.- The inner ring N is ofmagnetic material, preferably steel, while the outer coating is ofcopper or other good electrical conducting material. The .rotor is heldin position to the spider P by the screws Q, Q, etc., the arms of thespider being curved so that the rotor ring may expand when heatedwithout injury to the spider. The magnetic field casting has a long hubR extending from it which carries the two collector rings S, S, and,with the construction shown, the bevel gear H. Key T.(Fig. 2) serves tosecure,the gear to the hub. The collector rings are insulated from thesurrounding material by fiber rings and sleeves, but they are connectedby wires to the terminals of the field coils. The field casting isbushed as at W to withstand the wear and is separated from the spider bythe brass ring V. The spider is secured to the shaft by the key U.

- therein.

eddy currents will be generated,

From the construction above specified the magnetic flux will be asindicated by the lines X, X. .When this flux is present and there isrelative motion between M and K, which will takepaths similar to Z, Z,etc., and when the relative motion is, as shown by Y, the cur.- rentswill have directions shown by the attached arrows. Current is brought tothe collector rings by the wires 6 and 7 At 8 (Fig. 1) is a double throwswitch, which serves to connect either clutch circuit with .the linewires 9, and 10.

The operation of the electrical clutch machine is'as follows: The gear Erotates continuously in one direction driving both field castings but inopposite directions. The switch 8 is in a central position. The shaftits two spiders and their rotors. are at rest. When the operator wishesto start the shaft, he throws the switch in on one side. This allows thecurrent from the line to energize the field coils of one of theclutches. The magnetic flux X is thus set up. As the moving lines offorce sweep through the rotor, the heavy currents are generated Thesecurrents cause a drag between the fieldand the lOtOl, which drag willdrive the otor and thereby the spider and the shaft. When the operatorwishes 'the reverse shaft rotation, he throws the lever 8' in on theopposite side.

I am aware that, prior to my invention, electrical clutches of theinduction type have been used. These clutches have involved for a'rotora solid copper ring or disk arranged to run between two sets ofoppositely disposed poles, the magnetic flux thus passing flows throughthem adjacent oppositely disposed. The rotor straight from one polethrough the rotor to the opposite pole, but these clutches do not admitof such high starting'torques nor such low running slips as will the oneherein specified; furthermore, the rotors, which must be thin, aredelicate thus requiring large air aps, and are diilicult to connect tothe spi er.

With previous electrical induction clutches, in order to provide a pathof low resistance for the current, it isnecessary to shape the poles sothat they are narrow in the direction of rotation. This demands that thereversals of the heavy currents be so rapid that the self inductionpresent, will not permit of said heavy currents being as heavy asdesired.

A feature of my invention is the great length of poles allowable in thedirection of rotation while an easy path Z, Z, etc., is still available.It will be noted that with the copper in good electrical contact withthe steel, the conductivity of the path of the current is still furtheraugmented, for if the magnetic fluxadmits, at any point on the rotor,the heavy currents may take advantage of the steel as a'conductor andtake a still shorter path. With a clutch of this type, any reduction inthe slip, means not only an increased efiiciency, but an increasedcapacity, for the heating of the rotor will be less.

It was thought best to place the rotor on the outside ot the poles forin this latter position it is exposed to the cooling action of the air,increased by the tanning due to the revolving poles. To reduce the gapbetween the pole faces and the steel of the rotor ring, I may make theinside copper surface thinner than the sides and the outside surface.The construction of this copper covered rotor is made comparativelysimple, by the presence in the metal markets of copper clad steel madeby the new Monnot process. Having thus claim:

1'. In an electrical induction clutch, the combination of a field magnetand a rotor of magnetic material completely covered with a goodelectrical conducting material; said rotor bein revolubly mounted withrespect to said fiel magnet.

2. In an electrical induction clutch, the combination of a rotor and afield ma net having a common axis and mounted to a mit of relativerotations; said rotor consisting of a ring of magnetic material andcoating of good electrical conducting material which permits ofelectrical circuits around the magnetic material in planes which containthe axis; said field magnet having a plurality of poles arranged totransfer magnetic flux one to another, through the rotor.

3. In an electrical induction clutch, the

described my invention I rality oi radial combination of a field magnethaving a circular series of poles electrical Wmdmgsfor exciting adjacentpoles to opposite polarity;

.a rotor consisting of a ring of magnetic macombination. of a fieldmagnet having a plurality of poles in a plane perpendicular to the axisof rotation, and a rotor revolubly mounted in the plane of the magneticpoles; said rotor consisting of a rin of magnetic material and anattached envel oping coating of copper.

In an electrical induction clutch, the QOlilblIliltlOD of a shaft; afield magnet rev ohibly mounted on said shaft, said .field magnet havinga series of radial pole pieces in a plane perpendicular to the axis ofrotation; of electrical windings mounted on said pole pieces, connectedin such manner as would excite adjacent poles to op 'osite polarity;means for conveying electric current tosaid windings; a rotor spidersecured to said shaft; a copper clad steel rotor ring secured to saidrotor spider, surroundingsaid field magnet in the plane of said radialpole pieces and arranged to carry magnetic flux from each pole to theadjacent poles sub stantially as set forth.

6. In an electrical induction clutch, the combination of a fieldn'iagnet having a plupole pieces in a plane perpendicular to the axis ofrotation; of electrical windings mounted on said pole pieces,

connected in such manner as would excite adjacent poles toopposite/polarity; means for conveying electric current to saidWindings; and a copper clad steel rotor ring surrounding said polepieces revolubly mounted rotate the latter in one direction; drive cwith respect to saidfield magnet substantlally as set forth.

7. In an electrical induction clutch machine, the combination of adriving element; two electrical induction clutches, each 1 ing a drivinand a driven member; connections etween driving ei neat and one of saiddriving clutch niemhe nections between said driving element and theother oi. said driving clutch members to cause the latter to rotate inthe opposite direction; a driven element; drive connections between oneof said driven clutch members 'and said driven element to cause onedirection relation betwee the two; drive connections between the ot ierof said driven clutch members and said driven element to cause the samedirection relation between the two; and controlling means foralternately energizing the clutches.

8. In an electrical induction clutch chine, the combination of a drivingelement; two electrical induction clutches, each h ing a driving and adriven member; a di shafthaving said clutch driven members se cured tosame and having said clutch drivin'g members revolubly mounted thereon;a gearing connecting said driving element with one of said drivingclutch members to rotate the latter in one direction, a gearingconnecting said driving element with the other of said driving clutchmembers to cause the latter-to rotate in the opposite direction; andcontrolling means which operates to alternately energize the clutchessubstantially as set forth.

Witness my hand this 18th day of Novem- WILLMM r. Page.

- her 190?.

Viitnesses Geo. L. Tnnno, WA TER L. RUTH.

